The regimental museums of the Scottish regiments hold many sets of historic pipes given to them over the years. Reeds do not last long, but are really just consumables. Bags will become stiff and crack if not worked and fed, but again are easily replaced. The rest of the pipes are pretty indestructible if looked after, much like guns. They are mostly made of turned hardwood and silver. The bag cover and braids are usually wool and silk, and as long as they are kept out of direct light and the moths kept away, will last an extremely long time.
It used to be a standing myth that pipes were in the same part of the Stores Catalogue as small arms as they were considered to be weapons of war by the Regiments that used them. That said, I think demands for pipe replacements would be fed quickly through the system as they were considered a vital element in maintaining morale. I know the granddaughter of Piper Laidlaw, the Piper of Loos, who is still held in great regard by the Piping Mafia.
The Army School of Piping and Highland Drumming is in Redford Barracks in Edinburgh and has an interesting display of piping memorabilia. It is not open to the public, but it is probably worth asking for a visit if you are a true believer...
Wear Ear Protection..!